1. Field of the Invention
The present invention relates to methods of protecting read sensors from electrostatic discharge (ESD) damage during their manufacture.
2. Description of the Related Art
Read sensors of magnetic heads are sensitive devices which may be easily damaged during manufacturing by electrostatic discharge (ESD). During manufacturing, a plurality of magnetic heads are formed on a wafer. For each magnetic head, a read sensor is formed over a first gap layer (G1) which has a first shield layer (S1) formed beneath it. Above the read sensor is a second gap layer (G2) which has a second shield layer (S2) formed over it. The first and second gap layers and are made of an insulating material, such as alumina, whereas the first and second shield layers are made of a conductive material, such as Permalloy. Since these conductive materials are separated by the insulating materials, different electrical potentials may exist between the read sensor and shield layers. From the constant handling of the magnetic heads during manufacturing, electrostatic charge may undesirably build up and damage the read sensors. This may result in serious yield losses, especially as the sensor element becomes smaller in both film thickness and areal dimension.
Accordingly, there is a need to develop ways in which to protect read sensors from ESD damage during their manufacture.